Synthesis, growth mechanism and thermal stability of copper nanoparticles encapsulated by multi-layer graphene

Wang, Shiliang; Huang, Xiao-Lin; He, Yuehui; Huang, Han; Wu, Yueqin; Hou, Lei; Liu, Xinli; Yang, Taimin; Zou, Jin; Huang, Baiyun

doi:10.1016/j.carbon.2011.12.063

Cited by 200 publications

(140 citation statements)

References 47 publications

Supporting

Mentioning

129

Contrasting

Unclassified

Order By: Relevance

“…The first exothermic peak is probably attributed to the considerable oxidation process of Cu 2 O (major percentage of composition) to CuO, favored over the formation of copper carbonates. Similar findings were reported by Wang et al 46 Also, the oxidation of NaAlg with or without ring opening could take place for all stabilized Cu NPs. This can be explained by the oxidation of secondary alcohol groups of NaAlg to keto groups (without ring opening) and to dialdehyde or dicarboxylate derivatives (with ring opening).…”

Section: Thermal Characterizationsupporting

confidence: 90%

See 1 more Smart Citation

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Díaz-Visurraga¹,

Daza²,

Pozo³

et al. 2012

IJN

108

View full text Add to dashboard Cite

Background:The objective of this study was to clarify the intermolecular interaction between antibacterial copper nanoparticles (Cu NPs) and sodium alginate (NaAlg) by Fourier transform infrared spectroscopy (FT-IR) and to process the spectra applying two-dimensional infrared (2D-IR) correlation analysis. To our knowledge, the addition of NaAlg as a stabilizer of copper nanoparticles has not been previously reported. It is expected that the obtained results will provide valuable additional information on: (1) the influence of reducing agent ratio on the formation of copper nanoparticles in order to design functional nanomaterials with increased antibacterial activity, and (2) structural changes related to the incorporation of Cu NPs into the polymer matrix. Methods: Cu NPs were prepared by microwave heating using ascorbic acid as reducing agent and NaAlg as stabilizing agent. The characterization of synthesized Cu NPs by ultraviolet visible spectroscopy, transmission electron microscopy (TEM), electron diffraction analysis, X-ray diffraction (XRD), and semiquantitative analysis of the weight percentage composition indicated that the average particle sizes of Cu NPs are about 3-10 nm, they are spherical in shape, and consist of zerovalent Cu and Cu 2 O. Also, crystallite size and relative particle size of stabilized Cu NPs were calculated by XRD using Scherrer's formula and FT from the X-ray diffraction data. Thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry (DSC), FT-IR, second-derivative spectra, and 2D-IR correlation analysis were applied to studying the stabilization mechanism of Cu NPs by NaAlg molecules. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of stabilized Cu NPs against five bacterial strains (Staphylococccus aureus ATCC 6538P, Escherichia coli ATCC 25922 and O157: H7, and Salmonella enterica serovar Typhimurium ATCC 13311 and 14028) were evaluated with macrodilution, agar dilution plate count, and well-diffusion methods. Results: On the basis of the semiquantitative analysis, there was a direct correlation between the reducing agent ratio and the percentage of zerovalent Cu. This was confirmed with the statistical analysis of population of Cu NPs from TEM micrographs. At lower reducing agent ratios, two phases coexist (Cu 2 O and zerovalent Cu) due to incomplete reduction of copper ions by the reducing agent; however, at higher reducing agent ratios, the Cu NPs consist mainly of zerovalent Cu. Crystallite size and relative particle size of stabilized Cu NPs showed considerable differences in results and tendencies in respect to TEM analysis. However, the relative particle size values obtained from FT of XRD data agreed well with the histograms from the TEM observations. From FT results, the relative particle size and reducing agent ratio of stabilized Cu NPs showed an inverse correlation. The incomplete reduction of copper ions at lower reducing agent ratios was also confirmed by DSC studies. FT-IR and 2D-IR correl...

show abstract

Section: Thermal Characterizationsupporting

confidence: 90%

“…The first thermal event over 100°C may be attributed to the vaporization of physisorbed water from stabilized Cu NPs. 45,46 The second thermal event, starting over 160°C, was because of NaAlg degradation. 47,48 The weight loss between 160°C and 230°C was very fast and may be related to the biopolymer degradation.…”

Section: Thermal Characterizationmentioning

confidence: 99%

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Díaz-Visurraga¹,

Daza²,

Pozo³

et al. 2012

IJN

108

View full text Add to dashboard Cite

show abstract

“…By far, carbon-coated metal nanoparticles have been fabricated through numerous methods, such as arc discharge, 9 ion beam sputtering, 10 laser, 11 chemical vapor deposition, 12 high-temperature pyrolysis, 13 and detonation. 14,15 Among them, detonation method is the most method because of its facile process, low cost, and short reaction time.…”

Section: Introductionmentioning

confidence: 99%

Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

Ding

et al. 2017

AIP Advances

View full text Add to dashboard Cite

Carbon-coated copper nanoparticles (CCNPs) were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and copper nitrate hydrate (Cu(NO3)2·3H2O) in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM), high resolution transmission electron microcopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP) were also investigated by differential scanning calorimeter (DSC). Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne), and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger’s method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

show abstract

“…There exist various techniques to inhibit the oxidation of copper NPs, including coating them with noble metals 7,8) , self-assembled monolayers 9,10) , polymers 11) , or carbon-based materials 12,13) . Polyvinlypyrrolidone (PVP) makes a particularly interesting coating for the prevention of copper NP oxidation.…”

Section: Introductionmentioning

confidence: 99%

Application of the Taguchi Method to Optimize Graphene Coatings on Copper Nanoparticles Formed Using a Solid Carbon Source

et al. 2016

View full text Add to dashboard Cite

Graphene has attracted much recent interest as an electronic material due to its large electron mobility. Large-area graphene has been synthesized using chemical vapor deposition (CVD). However, it is dif cult to apply this process to grow graphene on nanoparticles (NPs) because of their small radius of curvature, which results in a large defect density. In this work, we used the Taguchi method to optimize the deposition of graphene on nanoparticles. We used polyvinylpyrrolidone (PVP) to coat copper NPs via CVD and optimized the process conditions using a minimal number of experiments. The PVP served as the solid carbon source, forming graphene when heated to 875 C. To improve the quality of the graphene coatings on the Cu NPs, the following process parameters were varied: gas conditions (ratio of Ar to H 2 ), process time and temperature, the amount of PVP solution, and the molecular weight of PVP. We identi ed optimal process conditions using only eight experiments. Raman spectroscopy was used to analyze the quality of the graphene coatings by comparing two-dimensional (2D) spectra and I D / I G ratios of the different coatings. A decrease in I D /I G , in combination with sharper Raman bands, is indicative of the thickness and crystal quality of the graphene layer. The quality of the graphene layer was also evaluated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM).The optimal conditions for the formation of graphene-coated Cu NPs were: a temperature of 875 C, a deposition time of 2 minutes, an Ar-to-H 2 ratio of 1:1, PVP with a molecular weight of M W = 3,500 (K-12) during the polyol process, and a 50-wt.% PVP solution with M W = 45,000 (K-30). Using the Taguchi method, we identi ed trends relating defect density versus process conditions and successfully obtained a graphene coating with a minimal defect density.

show abstract

Synthesis, growth mechanism and thermal stability of copper nanoparticles encapsulated by multi-layer graphene

Cited by 200 publications

References 47 publications

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

Application of the Taguchi Method to Optimize Graphene Coatings on Copper Nanoparticles Formed Using a Solid Carbon Source

Contact Info

Product

Resources

About